When individual persons or vehicles move through a transportation network, they are likely to be both actively and passively creating information that reflects their location and current behavior. In this patent, we propose a system that makes complete use of this information. First, through a broad web of sensors, our system collects and stores the full range of information generated by travelers. Next, through the use of previously-stored data and active computational analysis, our system deduces the identity of individual travelers. Finally, using advanced data-mining technology, our system selects useful information and transmits it back to the individual, as well as to third-party users; in short, it forms the backbone for a variety of useful location-related end-user applications.